Plastic container with plait formed pull tab



Jan. 19, 1965 s. w. AMBERG 3,166,234

PLASTIC CONTAINER WITH PLAIT FORMED PULL TAB Filed April 10. 1961INVENTOR. STEPHEN VV 14/ 75526;

Arrow/Ex:

MMM

United States Patent O 3,166,234 v PLASTIC CONTAINER WITH PLAIT FORMEDPULL TAB Stephen W.'Ambei'g, Syosset, N.Y., assignor to Lily-Tulip CupCorporation, New York, N.Y., a corporation of Delaware 7 Filed Apr.10,1961, Ser. No. 101,775 3 Claims. (Cl. 229-51) This invention relatesto containers and, more particularly, to plastic containers assembled toconstitutesanitacle has been filled with the materials to be packaged.

In such containers a relatively Weak bond is effected between thecover'and a flange or rim of the receptacle such as by forming them ofmutually immiscible substances and heat sealing them to close thereceptacle.

According to the prior art, the cover is removed in its entirety, andforthis purpose, in one embodiment of the prior art, the .cover, extendsoutwardly beyond an edge of the container to provide an outwardlyextending engageable marginal portion; while in another embodiment, theflanges of the container are cut away to permit engagement of the cover.v

I have conceived a completely new and different combination embodyingseveral advantages over the prior art including the facility of handlingthe filling and closing of containers, the ability to completely removethe cover by means of a readily engageable tab or handle disposed in aconvenient location on top of the cover while retaining the tab attachedto the cover during such removal.

As a feature of the invention, the receptacle has a peripheral flange orrim and the cover is severably secured to this rim, but the cover isfoldediback upon itself to form a plait extending across the open end ofthe-receptacle. The plait provides a finger grip by which the cover maybe grasped and torn completely away from the receptacle.

This form of plait pull tab, in addition to the advantage of beingdisposed in readily engageable position on top of the container,provides other substantial advantages over the prior art. To fullyappreciate these advantages, it is noted that in the production of thefilled individual small containers very substantial economies in timeand cost are obtained where the empty containers are joined together ina gang comprising several parallel rows of containers each comprisingseveral containers all connected together in the plane of the rimflanges to form a gang of containers which are filled in gang formationand then covered by a common sheet disposed over the gang and sealed tothe flange portions; thereafter the containers are severed from the gangto provide individual filled containers. In accordance with thisinvention, since the pull tabs are disposed on the top of the covers,the plaits for an entire row of containers may be formed across thecover sheet and the severance of the gang into individual containers maybe readily accomplished without disturbing the pull tabs. On thecontrary, in the prior art (referred to supra), where the handengageable portion of the cover is provided by extending the coverbeyond the edges of the container, such gang handling is prohibitedbecause in cutting or shearing the filled containers apart intoindividual containers it is not possible to leave the edge of the coverextending beyond the corre- 3,166,234 Patented Jan. 19,. 1965 ICCsponding edge of the container flange, as will be evident from MarshallPatent No. 2,736,656.

A further advantage of the invention is that the plait pull tabs of theinvention lie flat against the cover and are not disturbed when thefilled containers are stacked one upon the other in closely adjacentstakes; whereas in the prior art the overhanging edges are subject todistortion or even accidental rupture to the closure seal.

. As a further feature of the invention, the facing surfaces of theplait are secured together at the marginal regions thereof overlying theperipheral rim of the receptacle so that the sanitary integrity of thecontainer is assuredwhen cover and receptacle are secured together.Preferably, this feature is achieved by providing an adhesive coating onthe undersurface of the cover so that when the plaits are formed and thecovers secured to the receptacle rims, as by pressure and temperature,for example, the inner surfaces of the plaits will be sealed together atthose regions thereof that overlie the rims.

There has thus been outlined rather broadly the more important featuresof the invention in order that the detailed description thereof thatfollows may be better understood, and in order that the presentcontribution to the art may be better appreciated. There are, of course,additional features of the invention that will be described hereinafterand which will form the subject of the claims appended hereto. Thoseskilled in the art will appreciate that the conception upon which thisdisclosure is based may readily be utilized as a basis for the designingof other structures for carrying out the several purposes of theinvention. It is important, therefore, that the claims be regarded asincludingsuch equivalent constructions as do not depart from the spiritand scope of the invention.

A specific embodiment of the invention has been chosen for purposes ofillustration and description, and is shown in the accompanying drawing,forming a part of the specification, wherein:

FIG. 1 is a top plan view of a container in accordance with the presentinvention;

FIG. 2 is a front elevational view of the container shown in FIG. 1;

FIG. 3 is an enlargedview of a portion of the container shown in FIGS. 1and 2; and

FIG. 4is a perspective view illustrating an embodiment of the inventionshowing the cover in the stage of partial removal.

Referring now to the drawings in detail, and more particularly to FIGS.1 to 3 thereof, there is shown an individual portion container 10comprising a receptacle 11 which is formed of a suitable plastic such ashigh impact polystyrene, for example. The receptacle 11 is formed withtapered side walls and is shouldered as at 12 near its upper end forrigidity and stacking purposes, and is provided with a top opening'14(FIG. 4). A peripheral rim or flange 15 extends outwardly of the upperedges of the side walls and a cover 16 is substantially coextensive withthe flange and thus overlies the opening 14 at the upper end of thereceptacle. This cover 16 is removably secured to the rim 15 in a mannerand for a purpose to be later described.

According to the present invention, the cover 16 is folded'back uponitself to form a plait 17 external to the receptacle and which extendsacross the full width of the open end of the receptacle 11 in onedirection. The plait 17 thus forms a pull tab which may conveniently begrasped when it is'desired to open the container. Preferably, the cover16 is coated on its under surface with a 3 7 while avoidingfusing of thematerials and, preferably even distortion thereof. Such sealing may beeffected at a temperature between 200 F. and 220 F., and prefer-' ablyat approximately 210 F. for a dwell of about one second andv under apressure of the order of 40 pounds per square inch for a singlecontainer and cover.

Since the underside of the cover is fully coated with the adhesive, itwill be appreciated that as the cover is sealed to the rim 15 of thereceptacle, sealing will also occur between opposed surfaces of theplait 17 itself at its marginal ends overlying the rim 15, thus toassure the complete sealing of the container.

Referring now to FIG. 4, the cover 16 is formed of a tough plasticfilmwhich resists tearing. It has been found that a polyester film such aspolyethylene terephthalate sold by duPont under the name Mylar iseminently suitable for this purpose.

Accordingly, when the plait is grasped and pulled in the directionindicated by the arrow in FIG. 4, the cover 16 resists tearing along theplait crease lines, but rather, the adhesive seal between the cover 16and rim or flange 15 is broken and the cover is peeled from the flange15 whereby the cover 16 may be completely severed from the receptacle11.

It will be understood that in the manufacture of the containers, thereceptacles may be arranged conveniently in gang formation, filled,covered with a common plaited sheet as'above described, and sealed; andthereafter individual sealed containers severed from the gang.

Since the film for the cover 16 is a relatively tough material, it maybe and preferably is made relatively thin for purposes of economy and tofacilitate removal. For example, such material having a thickness ofabout .001" has been found entirely satisfactory forportion sizecontainers, with somewhat thicker covers being desirable for containersof larger'size.

From the foregoing description, it will be seen that I have contributedan improved sanitary disposable plastic portion container having theadvantages above noted.

I believe that the construction and utilization of my novel containerwill now be understood and that the advantages thereof will be fullyappreciated by those persons skilled in the art.

What I claim is:

l. A plastic container comprising a receptacle having an integralperipheral rim both formed of a plastic and a cover overlying the openend of said receptacle and formed of a tough, tear resistant plastic,said cover being folded back upon itself along parallel crease lines toform a manually engageable plait extending across the open end of saidreceptacle, the lower surface of the margin of said cover beingseverably adhered to the upper surface of the rim of said receptacle andthe facing surfaces of said plait being secured to one another at themarginal ends thereof overlying said rim, said plait extending acrosssaid receptacle to its open end including said rim flange and being freeto pivot about its juncture with said cover, the folds of said plait atsaid pivotal juncture being substantially stronger than the severableadherence between said cover and the upper face of said rim flange,whereby a tension force exerted on said plait peels the cover from therim flange while leaving said plait attached to said cover.

2. A plastic container comprising'a receptacle having an open enddefined by a peripheral rim flange, and a receptacle cover overlying theopen end of said receptacle and severably secured to the upper face ofsaid rimflange in superimposed. relation. to form therewith a two plylaminate, one ply of which is readily peelable from the other, saidcover being folded back upon itself alongv an inner fold line to form aninner foldv and along an outer fold line to form an outer fold, saidinner and outer folds conjointly forming a manually engageable plaitextending across said receptacle at its open end including said rimflange and being free to pivot about said inner fold line relative tosaid cover for the full length of said plait, the inner and outer foldsof said plait adjacent said pivotal juncture being substantiallystronger than the severable securing means between said cover and theupper face of said rim flange, whereby a tension force exerted on saidplait peels said cover from said rim flange while leaving said plaitattached to said cover.

3. A container'comprising a receptacle having an open end defined by aperipheral rim and a plastic cover therefor overlying the open end ofsaid-receptacle and said rim, said cover being folded back upon itselfalong inner and outer fold lines to. form a plaitextending across thefull width'of'fthe open endof said receptacle on the side i of saidcover away from said receptacle so as to constitute a pull tab, theinner surface of said cover being peelably secured to the rim of saidreceptacle, said plait being free to pivot about said inner fold linerelative to said cover for the full length of said plait, the inner andouter folds of said plait .adjacent said pivotal juncture beingsubstantially stronger than the severable securing means between saidcover and the upper face of said rim flange, whereby a tension forceexerted on said plait peels said cover from said rim flange whileleaving said plait attached to said cover.

References Cited in the file of this patent UNITED STATES PATENTS2,062,278 Vogt Nov. 24, 1936 2,973,087 Rohdin Feb. 28, 1961 2,990,948Zackheim July 4, 1961

1. A PLASTIC CONTAINER COMPRISING A RECEPTACLE HAVING AN INTEGRALPERIPHERAL RIM BOTH FORMED OF A PLASTIC AND A COVER OVERLYING THE OPENEND OF SAID RECEPTACLE AND FORMED OF A TOUGH, TEAR RESISTANT PLASTIC,SAID COVER BEING FOLDED BACK UPON ITSELF ALONG PARALLEL CREASE LINES TOFORM A MANUALLY ENGAGEABLE PLAIT EXTENDING ACROSS THE OPEN END OF SAIDRECEPTACLE, THE LOWER SURFACE OF THE MARGIN OF SAID COVER BEINGSEVERABLY ADHERED TO THE UPPER SURFACE OF THE RIM OF SAID RECEPTACLE ANDTHE FACING SURFACES OF SAID PLAIT BEING SECURED TO ONE ANOTHER AT THEMARGINAL ENDS THEREOF OVERLYING SAID RIM, SAID PLAIT EXTENDING ACROSSSAID RECEPTACLE TO ITS OPEN END INCLUDING SAID RIM FLANGE AND BEING FREETO PIVOT ABOUT ITS JUNCTURE WITH SAID COVER, THE FOLDS OF SAID PLAIT ATSAID PIVOTAL JUNCTURE BEING SUBSTANTIALLY STRONGER THAN THE SEVERABLEADHERENCE BETWEEN SAID COVER AND THE UPPER FACE OF SAID RIM FLANGE,WHEREBY A TENSION FORCE EXERTED ON SAID PLAIT PEELS THE COVER FROM THERIM FLANGE WHILE LEAVING SAID PLAIT ATTACHED TO SAID COVER.